Damper



Nov. '4 1924.

T. H. CONWAY, SR

' DAMPER Filed April 19. 1923 INVENTOR.

' ATTORYNEY.

Patented Nov. 4, 1924.

tlNH lE-D STATES PATENT orrice.

THOMAS H. CONWAY, SR., 035 DETROIT, IYrIICTrIIGAN.

DAMPER.

Application filed April 19, 1923.

lines, and has for its object an improved construction whereby not only may the de gree of opening or closure of the damper be easily and accurately regulated from without, as for example a point on the front or exposed surface of the grate wall, but it concerns as well the pivotingof the damper plate in such a way that, when thrown open, substantially the entire crosssectional extent of the flue maybe rendered available for the upward passage of the products of combustion without splitting the draft, that is, requiring that the upward air current bedivided so as to pass on each side of a centrally pivoted damper plate.

Figure 1 is a perspective ofmy' improved construction with the damper plate shown in almost fully open position.

Figure 2 is a vertical cross-sectional view, with the damper in closed position.

Figure 3 is a similar cross-sectional view, taken along the line 3--3 of Figure 1, showing the damper in raised position.

Figure 4k is a fragmentary elevational view of the damper plate and of the cam viewed from the opposite direction from that from which Figure 1 is taken.

Figure 5 is an edge elevational view of the cam on a somewhat enlarged scale.

A represents arectangular dome frame for a flue with its bordering edges A adapted to be built into the wall. The tapering side walls A have their end sections provided with sockets B, in which are journaled the triulnion ends C which project from correspondingly located positions on the ends of the damper plate D. A ridge or rib F is preferably located on the under side of the damper plate D in such position as to be engaged by the notched surface of the eccentric or cam piece G, which is carried on the inner end of the shaft- .H. This a center.

Serial No. 633,053.

latter rotatably engages through the bearing J in the flue wall, and on its outer end is mounted the handle K, by means of which its rotative actuation may be accomplished when the opening or closing of the damper plate is desired.

lVhen the plate D is in closed position across the throat of the fine, the wiping edge of the cam G engages the rib F with a point on its periphery which is located relatively near .to the shaft J; and its point ofcontact with the rib F is relativelynear the front or free edge of the plate D. \Vhen,

however, the shaft J is rotated, the increaseccentric ity of the peripheral edge of the cam which is drawn against the rib F results in raising of the free edge of the plate about its trunnion projections B as It is in the early stages of the lifting movement that the greatest lifting force of the cam upon the plate is required, and consequently its positioningnear its forward unpivoted edge is desirable. *When, however, the lifting of the plate, through a 45 degree angle for example, has been effected, this factor diminishes, the principal,

requirement then being a tendency to throw the plate D back to a vertical position; to care for this, that portion of the cam lying, for example, between the peripheral points Xand Y is inclined away from the plane of the portion of the cam which was first active, thus not only more closely following the rib F as it is raised and thrown baclrward, but its point of frictional engagement therewith actually traveling along the rib F toward. the rear or pivoted edge of the plate D", so as to effect a greater throw of the pivot plate in degrees proportionately to the degree of turning of the pivot H than is the case in the earlier lifting stages. Similarly when the closure movement of the plate is desired, the reverse of this described action as regards the wiping movement of the cams periphery against the rib F takes place.

The plate D is preferably not designed to be raised to quite a fully vertical position. The difference in the cross-sectional area of the open part of the flue throat is so slight, however, as to be negligible, and in any event is much less than the diminution in the cross-sectional area of the flue threat in case the damper plate D is centrally pivoted, as has heretofore been the practice, so that the upwardly traveling current of connections of the plate, and is adapted to liftingly engage the under face of the plate, that portion of the cam which engages the plate in the later stages of its rotative actuation being bent away from the plane of the central portion, whereby it engages points on the under surface-of the plate increasingly near its trunnion axis as the lifting movement progresses.

2. A dome damper, having, in combination with a laterally pivoted closure plate adapted to regulate the possible draught flow through a chimney flue, an externally actuatable cam therefor whose plane is generally parallel to the axis of turning of said closure plate, certain portions of the engaging periphery of said cam being bent away rom the plane of the remainder thereof, whereby, as it is rotated, the point of its contact with the under surface of the plate moves toward the rotative axis of the plate during its lifting and away therefrom as the plate is lowered toward closure po sition. i

3. A dome damper, having, in combination with a closure plate adapted to turn plate moves transversely of the axis of turning thereof.

t. The combination, with a rectangular flue throat, of a laterally journaled closure plate therefor, and an externally actuata-ble cam member adapted to frictionally engage the under side of said closure plate to eii'ect its upward swing, said cam having that portion of its body containing its highest point curved from the plane of its center portion in a direction to cause additional rearward throw to the closure plate as its opening movement approaches its maximum.

5. In combination with a closure plate journaled to swing approximately about one of its long sides as an axis, a. lifting cam adapted to wipingly engage the under face thereof from a point near its free side toward its journaled side, the outer peripheral portion of the (111111. being inclined,

away from the center portion to bring about added throw of the plate toward its extreme upper position as the lifting movement progresses.

In testimony whereof, I sign this specification in the presence of two witnesses. I

THOMAS H. CONWAY, SR.

Witnesses:

hhnennnrrn KEENAN, HARRY F. PIsULA. 

